Springerville Generating Station

Owners: TEP (Units 1 and 2); Tri-State Generation and Transmission (Unit 3); SRP (Unit 4)

Operator: TEP/UniSource

Location: Springerville, Arizona

Description: Springerville Generating Station (SGS) is a state-of-the-art coal-fired power plant that will assure fuel diversity for a secure Arizona energy future and also enhance national energy security by using a dependable, domestic fuel source.

Total generating capability: Units 1 and 2 each bring 380 MW, for a total of 760 MW. Unit 3, which began operation in 2005, adds 400 MW for a combined total of 1,160 MW. Unit 4 was completed in December 2009, adds another 400 MW, bringing the facility's expected capacity to 1,560 MW.

Fuel source: Low-sulfur coal

Plant construction: Units 1 and 2 were completed in 1985 and 1990, respectively. Unit 3 was completed in summer 2006. Unit 4 was completed in December 2009.

Plant operations: Springerville supplies power to Tucson Electric Power (TEP), Tri-State Generation & Transmission, and the Salt River Project (SRP). Air emission controls on Unit 4 will meet EPA's Best Available Control Technology (BACT) requirements. Furthermore, emission controls on Units 1 and 2 were upgraded as part of the plant expansion. As a result, emissions from all four units will be less than the original two units.

Currently, power from SGS units 1,2 and 3 is transmitted to Tucson and into the grid serving Arizona. In addition, some of the SGS energy is used by Tri-State Generation & Transmission, a Denver-based wholesale power cooperative with member distribution systems in Colorado, New Mexico, Wyoming and Nebraska.

The plant utilizes a proven and dependable water supply. Well fields that supply the four units are from aquifers deeper and separate from the aquifer that the towns rely on.